I've been using Jitsi and Google Hangouts for years, and in terms of reliability/quality, I can't really tell any difference. Haven't used Zoom much.

The nice thing about about Jitsi is it's the most simple process I've seen: just tell people to go to a simple vanity URL (URL you get to design) and that's all. I sometimes find Hangouts confusing with all the invitation, accepting, etc.

For people I videochat with often, I just say "jump on Jitsi?", then start typing in URL bar which autocompletes and boom, we're chatting

Used it several times, it's reliable.

It's reliable, especially for one-on-ones or smaller groups with particpants that have good bandwidth internet connections. In terms of bandwidth needs it can't compete with Zoom yet. If you have bigger meetings with participants from all over the world, and would like to use video, I wouldn't recommend it at the moment.